The history of Thalíär remains a mystery.

On this point, I must first acknowledge the salience of my colleagues’ reports.  The various shafts, canyons, and large-scale gaps in the upper and middle planetary surfaces do not occur in any geometric, fractal, or other discernible ordered pattern, nor do the edges of these phenomena appear even as regular as cleavage planes, or to bear tool-marks.  Variation in atmospheric pressure from the uppermost point of the planetary surface (Sardal’s Peak) to the lowest (the Undersea surface at the Thunder Well), a distance of 3.2 miles, follows natural expectations based upon its composition and the low planetary gravity.  The planetary ecology shows no signs of engineering, and while partially differentiated across the world’s layers, clearly shares a common origin.  There are no signs of artificial constructions, including the absence of convenient or evidently engineered paths between layers, and the walls and pillars which support the middle and upper crusts appear to be entirely composed of native rock, with no trace of exotic materials familiar to us from known Precursor megastructures, or indeed presently unknown.  All these factors, while not in themselves conclusive, are indeed suggestive of a non-artificial origin for this planet.

Nonetheless, I and my survey team are unanimous in concluding that no known geophysical mechanism could result in the triple-crust shell-world structure seen here on Thalíär, nor have we been able to postulate or simulate any mechanism or combination of mechanisms that could result in this or any similar structure.  While this is no more conclusive than the circumstantial evidence for natural origin listed above, our inability to construct a reasonable hypothesis to explain Thalíar’s structure in natural terms, in the light of our studies of the hundreds of planets so far examined in detail by the Exploratory Service, strongly suggests that Thalíär is nonetheless a construct.

In summary, therefore, the Thalíär Expedition concludes that it has no damned idea how this world came to be, nor, in the absence of new evidence, new exploratory techniques, or the artist’s signature coming to light, does it expect this situation to change in the near term.

– Geologist Excellence Cymnea Steamweaver,
reports on the Thalíär (Principalities) shell-world